Paving material and process of making same



Patented June 5, 1934 UNITED STATES PAVING MATERIA L AND PROCESS OF MAKING SAME James T. Sweeney, Scranton, Pa., assignor to Sweeney Br0s., Scranton, Pa., a corporation of Pennsylvania No Drawing. Application March 7, 1932 Serial No. 597,430

3 Claims.

The present invention relates to a new and improved surfacing material and process of forming the same which is especially adapted for use as a paving or covering for streets, floors and the like.

In certain localities which are subjected to surface disturbances such as mining regions, serious difiiculty has been encountered in obtaining a paving surface which would not crack or be detrimentally affected when subjected to such disturbances.

One of the important objects of the present invention is to utilize the refuse material from coal cleaning plants as the basic ingredient of an aggregate forming the paving material. This refuse, which is composed of anthracite slate and mine rock, possesses certain inherent characteristics which renders it admirably suited for use in paving material as it is relatively light in weight and may be easily handled. Moreover, as this refuse material has previously been passed through the coal cleaning plant and subjected to a sand flotation treatment, it is practically free from coal, dirt and other foreign particles.

The slate constituting a part of the refuse material is a black stone that lies between the rock and the vein of coal and contains a per centage of carbon. Not infrequently, this slate is referred to in mining regions as bone and it is this bone or anthracite slate that forms with the mine rock the refuse material which, when mixed with a bituminous binder, forms my improved yieldable paving composition. As there are no slate quarries in the anthracite coal regions, it will be seen that the anthracite slate or bone constituting a part of the refuse material is substantially different in its properties and characteristics from ordinary slate rock.

The refuse material of slate or bone and mine rock is preferably mixed with a bituminous binder such as tar or asphalt at a temperature of between 250 to 300 F. and in order to provide a durable and rigid paving surface, sand and limestone dust may be added in varying proportions.

I have found that a paving composition consisting substantially of 58% refuse material, that is, about 29% anthracite slate or bone and 29% anthracite mine rock, 6 to 12% of a bituminous binder such as asphalt or tar or other liquefied material either hot or cold, 30% sand, and 5% limestone constitutes a mix, which when spread and rolled on the surface to be covered and allowed to harden, forms a light flexible paving composition of such a durable construction as to be capable of withstanding the hard usage to which such a paying surface is subjected and will readily accommodate itself to any irregularity in the surface or bed on which it is applied. The economy of producing the refuse material is enhanced, due to the fact that the mixture may be reclaimed and salvaged and used again where it is required to be removed. Additionally, in localities which are subjected to surface disturbances, a paving mixture formed in accordance with the present invention may be economically and. successfully employed, since, should it become cracked, it has the tendency to knit itself together without materially impairing its otherwise durable wearing ualities.

The coarse aggregate of anthracite bone or slate and mine rock is preferably used in sizes of from ,4 to 1 and may be mechanically mixed with the tar or asphalt or may be clipped or saturated in a bituminous binder so as to be completely covered or coated with the tar or asphalt and then spread and rolled on the surface to which it is to be applied.

It is to be understood that the paving composition and process of making the same as herein set forth are merely illustrative and that such changes may be made as fall within the purview of one skilled in the art and the scope of the appended claims.

I claim:

1. A flexible paving material of the class described including coarse aggregate refuse material of anthracite bone and mine rock from coal cleaning plants, a filler, and a bituminousbinder, the coarse aggregate refuse material varying in size from between to 1 2. A flexible paving composition of the class described including refuse material of anthracite bone and mine rock from coal cleaning plants and a mixture of sand, limestone dust and a bituminous binder, the flexible properties of the composition permitting it to accommodate itself to any irregularities on the surface to which it is applied.

3. A flexible paving composition of the class described including substantially 60% of refuse material of anthracite bone and mine rock from coal cleaning plants, 6 to 12% of a bituminous binder, substantially 30% sand, and substantially 5% limestone dust, the yieldable properties of the composition permitting it to accommodate itself to any irregularities on the surface to which it is applied.

JAMES T. SWEENEY. 

